The present invention relates to an internal paddle electrode having an electrode which is to be in direct contact with the heart (living body) of the patient.
An internal paddle electrode of this kind is used in the following manner. The heart of the patient is interposed between a pair of electrodes, and a voltage from a defibrillator is applied to the heart. A known internal paddle electrode is of a type in which an electrode can be separated from a handle. The internal paddle electrode is configured so that the handle can withstand sterilization (see JP-A-5-337193, particularly see paragraph 0027).
On the other hand, there is also an internal paddle electrode of a type in which an electrode cannot be separated from a handle. The handle is required to be washed and sterilized by flowing water or the like. However, the electrode and the handle do not have a hermetically sealed structure. When washed with flowing water, therefore, blood and the like penetrate through a gap between the electrode and the handle, and hence blood and the like are wiped off with a cloth or the like.
After wiping, the internal paddle electrode is sterilized in the following manner. A sterilizing process which is called autoclave, and in which a process where sterilization is performed at a pressure of about 2 atm. and a high temperature of 130 degrees Celsius for about 10 to 20 minutes, and thereafter the normal pressure is introduced by reducing the pressure is repeated. In the case where the electrode and the handle have a hermetically sealed structure, washing with flowing water is enabled, but, when autoclave sterilization is performed, the internal pressure of the handle becomes higher than the external pressure because the handle has a hermetically sealed structure. Therefore, there arises a problem in that a cover covering the outside of the handle is expanded to be deformed.